Exercise devices such as barbells are used for weight training. The barbell comprises a bar having a first weight. A user may do weightlifting exercises with the bar alone for training. Alternatively, the user selects a pair of weights and releasably secures one weight to each end of the bar. A number of pairs of differently sized weights are provided so that a user may select a total weight with which to exercise. In another form of exercise device, a barbell is formed with a yoke portion. Rather than doing lifting exercises, the user places the barbell over the shoulders, with the yoke going behind the neck. The user may perform trunk twists and bends using the bar to maintain positions of the arms and torso for maximum effectiveness of the exercises. The bar is configured for adding weight inside or outside and particularly at its ends for increasing the rotational moment of inertia of the bar to give the effect of greater weight.
An example of a trunk exerciser is shown in U.S. Pat. No. 5,312,314. An exercise bar includes a yoke. In one form, the exercise bar comprises five sections that fit in a carrying case. In one embodiment, weights can be inserted in hollow ends of the bar. End caps are press fit over the ends of the bar. The range of weight that can be provided is necessarily limited by the space inside the ends of the bars. In another embodiment, weights are inserted over an exterior of each end and held in place by a collar including a setscrew. The end cap and the setscrew each provide for an interference fit rather than positively retaining the cap or collar in place with a stop element. In another form, weights are retained on each end of the bar by a screw with a broad head threaded into an end of the bar. The screw does not permit quick release or engagement of the retained weights.
U.S. Pat. No. 5,295,934 and U.S. Pat. No. 6,007,268 each disclose a locking release collar assembly received over a bar. The collar is adapted to be axially received on and to be removably fixed at a selected location axially between a weight mounted on the bar and an end of the bar. The release collar includes an assembly in which radially moveable ball detents are cammed into frictional engagement with the shaft and rest in a groove. A spring-biased collar member is moved axially to permit the ball detents to move radially outwardly out of the groove to unlock the release collar. In this construction, a weight cannot be mounted on an end of a bar. The weight must move axially inwardly of the end of the bar. The release collar is an additional component which must be provided in addition to the weight and the bar. This structure does not provide for securing a weight to an end of the bar. As a practical matter, a user must apply force to circumferentially opposed portions of the collar. These collars are not operated by a single application of force to a single location such as a button.
U.S. Pat. No. 4,854,576 discloses weights each integral with a collar that slides on to the end of the bar. A spring clip inside the bar radially biases each of two radially opposed detent pins outwardly through holes in the bar into recesses in the collar. To release a weight, a user must push fingertips through the holes to push the pins into the bar. There is no mechanism to operate the pins outside of the holes or to keep the pins in a radially inward position when the user's fingers are removed. Also, the collar exerts a shearing force against the pins which can also exert a moment on each pin tending to pull the pin from the spring clip. A detent mechanism immune to the generation of force moments is not provided.
The prior art does not disclose a system for retaining a weight on an end of a bar which is positively operable between an engaged and disengaged position and in which in a retainer assembly separate from the bar or the weight is not required.
The above cited art discloses bars which may be used with a pair of weights that is selected from a set of a plurality of pairs of weights. Systems utilizing a set of pairs of weights may include a rack or cabinet to support the pairs of weights. However, the weights generally rest on a rack and do not engage a support in a manner similar to that in which the weights would engage the bar.